Prolonged antidiuresis by 1-desamino-8-D-arginine vasopressin (DDAVP): correlation to its plasma levels and nephrogenous cyclic AMP production.

In an attempt to clarify the mechanism responsible for the prolonged effect of DDAVP (1-desamino-8-D-arginine vasopressin), plasma levels of DDAVP and nephrogenous cyclic AMP were determined in patients with diabetes insipidus after a single intranasal administration of 10 micrograms of DDAVP. Plasma DDAVP levels were uniformly elevated within 30 min, and showed a peak ranging from 5.6 to 25.0 pg/ml between 30 and 120 min. The subsequent time-course of plasma DDAVP differed however, from patient to patient, and was irregular in most of them. In all of the patients whose plasma DDAVP dropped below 1.0 pg/ml, antidiuresis was still observed. Although the mean basal level of nephrogenous cyclic AMP in patients with diabetes insipidus was not significantly different from that in control subjects, the administration of DDAVP resulted in a 2-fold increase. A negative correlation between nephrogenous cyclic AMP and free water clearance was obtained. These results suggest that the long-acting nature of DDAVP may be attributed, in addition to its gradual absorption from nasal mucosa and slow metabolic clearance, to a higher or persistent biological activity at the receptor site in the kidney and that a nearly physiological level of antidiuretic hormone may cause de novo synthesis of cyclic AMP in the kidney and exert its biological action.